A 68-year-old man comes to the office due to right knee pain and swelling. Three days ago, the patient spent most of the day on his knees while replacing the kitchen floor. The next day, the right knee started to become increasingly red and painful. Medical history includes hypertension and type 2 diabetes mellitus. Temperature is 37.8 C (100 F), blood pressure is 130/80 mm Hg, and pulse is 92/min. On examination, erythema and warmth are present at the anterior right knee, as shown in the exhibit. Palpation reveals a 5-cm, tender, fluctuant swelling just anterior to the patella. Range of motion of the knee is intact but produces mild pain at the end-range of flexion and extension. Pedal pulses are 2+, and sensation in the lower extremities is intact. Gait is normal. Which of the following is the most appropriate next step in management of this patient?

Question

A 68-year-old man comes to the office due to right knee pain and swelling.  Three days ago, the patient spent most of the day on his knees while replacing the kitchen floor.  The next day, the right knee started to become increasingly red and painful.  Medical history includes hypertension and type 2 diabetes mellitus.  Temperature is 37.8 C (100 F), blood pressure is 130/80 mm Hg, and pulse is 92/min.  On examination, erythema and warmth are present at the anterior right knee, as shown in the exhibit.  Palpation reveals a 5-cm, tender, fluctuant swelling just anterior to the patella.  Range of motion of the knee is intact but produces mild pain at the end-range of flexion and extension.  Pedal pulses are 2+, and sensation in the lower extremities is intact.  Gait is normal.  Which of the following is the most appropriate next step in management of this patient?

Quizplus · Accepted Answer

11ec25c8_d86c_0ee9_bc81_85db1f522228_MD0003_00 This patient's presentation is concerning for septic bursitis. The prepatellar bursa is a fluid-filled synovial sac between the patella and the skin that alleviates friction. Infection of the bursa can occur due to penetrating trauma, superficial abrasions (eg, from working while kneeling), or extension from local cellulitis. Gram-positive skin floras (eg, Staphylococcus aureus) account for most cases, and the risk is greater in patients with immunocompromising conditions (eg, diabetes mellitus). patella and the skin Septic bursitis is characterized by boggy swelling of the bursa associated with erythema, warmth, pain, and fever, although fever may be less prominent in patients age ?65. Aspiration of bursal fluid is necessary to confirm the diagnosis; the fluid should be sent for cell count and differential, Gram stain, and culture. Treatment includes systemic antibiotics; drainage is indicated when the bursitis fails to improve after 36-48 hours of antibiotic therapy or compressive symptoms (eg, neurovascular compromise) are present. (Choice B) Knee joint (rather than bursal fluid) aspiration is indicated for suspected septic arthritis, which presents with knee effusion and severely painful, reduced range of motion. This patient has intact range of motion of the knee with little pain, indicating that the pathology is extraarticular. (Choice C) Gout can cause an inflammatory bursitis resembling septic bursitis, and bursa fluid is often sent for crystal microscopy. However, gouty bursitis is significantly less common than septic bursitis, and infection should be ruled out before empirical treatment for gout (eg, colchicine) is initiated. (Choice D) A knee compression wrap and ice application are used to treat noninflammatory bursitis due to overuse. This patient's erythema and warmth are atypical for noninflammatory bursitis. In some patients, it may be hard to differentiate septic from noninflammatory bursitis. Therefore, aspiration should be performed to rule out infection. (Choice E) Knee x-ray may show nonspecific bursal swelling but does not rule out infection. X-ray is most helpful if a concurrent fracture (eg, due to a fall) or foreign body is suspected. bursal swelling Educational objective: Septic prepatellar bursitis is characterized by acute erythema, warmth, and pain accompanying bursal swelling. It is usually caused by skin breakage that allows entry of skin floras (eg, Staphylococcus). Bursal fluid analysis is needed to confirm the diagnosis. Treatment includes systemic antibiotics.

A 68-Year-Old Man Comes to the Office Due to Right